Limits (p-1) — Maths (commerce) STD 11 Commerce / Arts — Question

\begin{aligned} \text { If } \mathrm{f}(\mathrm{x})=\frac{5^x+5^{-x}-2}{x^2}, \text { for } x \neq 0 \\
=\mathrm{k} \text { for } \mathrm{x}=0
\end{aligned}

The following data gives the age of 100 students in a school. Calculate variance and S.D.

Age (In years)	10	11	12	13	14
No. of Students	10	20	40	20	10

A bag contains 50 tickets, numbered from 1 to 50 . One ticket is drawn at random. What is the probability that: number on the ticket is a perfect square or divisible by 4 ?

Find k, if the following equations are consistent.

(ii) (k – 2)x + (k – 1)y = 17, (k – 1)x + (k – 2)y = 18, x + y = 5

Find the square roots of : 2 + 2√3i

The following table gives the weights of the students of class A. Calculate the coefficient of variation (Given √8 = 0.8944)

Weight (in kg)	Class A
25-35	8
35-45	4
45-55	8

The city traffic police issued challans for not observing the traffic rules:

Day of the week	Mon	Tue	Wed	Thus	Fri	Sat
No. of challans	40	24	36	58	62	80

Find Q.D.